The present invention relates to a small engine, and particularly, to a small engine suitable for portable engine work machines, such as a string trimmer and a chain saw, and an engine work machine including the same.
Two-cycle engines, for example, as shown in JP-A-7-253033, has a governor which cuts off an air-fuel mixture passage to prevent over-rotation of the engine in a case where the rotational frequency of the engine increases to a predetermined rotational frequency or higher.
Meanwhile, in the governor of JP-A-7-253033, an air-fuel mixture is not supplied in the case where the rotational frequency of the engine increases to a predetermined rotational frequency or higher. Thus, over-rotation is suppressed, and emission of unburned gas is also eliminated. However, since the governor does not operate at a predetermined rotational frequency or less, there is a problem in that unburned gas may be emitted to the outside in a case where combustion has not been performed within a cylinder.